DE4229693A1 - Electrotherapeutic device - Google Patents

Abstract

The invention concerns a device operating in the medium-frequency range between 1,000 and 100,000 Hz and designed for electrotherapy applications. An electrical circuit is set up through the part of the body to be treated, a medium-frequency (MF) current being passed through two electrodes. The invention calls for the amplitude of the MF current to be held constant and for the frequency to be modulated by a thousand to several thousand hertz (cut-off frequencies) at a modulation frequency of >/= 0 to a few hundred hertz (e.g. 200 Hz) in order to generate action potentials in the treatment area which are synchronous with the modulation frequency.

Description

The present invention relates to a medium frequency Rich between 1000 Hz and 100000 Hz working device for elec trotherapeutic applications, with reference to one to behan The body part is diametrically opposed in pairs Electrodes are applied.

It has been known for a long time and in this respect is also used electro-therapeutically, excitable cells (nerves, muscles and receptors of nerve endings) of the human body through electrical stimuli, which are supplied in the form of electrical impulses from the outside, to an electrical response, the so-called called action potentials (see. Fig. 12) to force. These action potentials are cell-specific electrical impulses with a defined height and width for the respective cell type. For a nerve, the pulse width of approx. 1 ms and the height of approx. 80 mV-100 mV are typical. The cell uses its cell membrane voltage, which at rest, depending on the cell type, has a value between 60 mV and 120 mV. This voltage is caused by different ion concentrations in the extra- and intracellular spaces, which are separated by the cell membrane. There are more positive ions outside the cell. By definition, the potential outside the cell is set to 0 V, so that there is a negative potential in the cell (see FIG. 12).

In healthy people, the body's potential for action generated and for the transmission of information and for triggering Cell processes used. In electrotherapy are targeted through Generation of action potentials (defined number and at be certain places) produces therapeutic effects.

In known devices for electrotherapy, a variety of different current or pulse forms related. With the Be The therapist strive to provide the most appropriate electrotherapy for the indication in the (specific) individual case he should choose criteria that are as clearly defined as possible can. These criteria result from the answer asked questions about the effectiveness and tolerability of the different forms of current.

The spectrum of effects includes z. B. the areas of Pain relief, irritation of striated and smooth Muscles, the blood circulation, the metabolism influence, decongestant mechanisms, inflammation inhibition and promotion of regeneration (wounds, be accelerated bone healing). The application should always be tried by choosing the correct current form the desired effects in the affected area, either near the electrodes or electrode distant or in the depth of the body to achieve.

With regard to compatibility, it should be ensured that the current caused no damage both systemically and locally.

The main concern is the systemic compatibility of currents Lich by the ventricular fibrillation threshold and the risk of out solution of epileptic seizures. That means that the therapeutic area as far away from these thresholds should be. It is therefore preferable to use currents where these Thresholds are particularly high.  

Local tolerance is due to the risk of burns and burns, as well as determined by the pain threshold.

Accordingly, currents and pulse forms are preferable in which the desired effects occur without the patient ir any negative side effects felt.

Basically, in the known electro therapy devices from two stimulus current methods, the polarity-dependent "Polaritarian stimulus principle" and the polarity-independent "Apolarit principle of irritation ".

In the "polaritarian stimulus principle", low-frequency currents (Nf- Current) worked from 0-200 Hz. Under the positive electrode, the Anode, hyperpolarization occurs (membrane increase voltage), which means the distance between the potential in the cell le and the stimulus threshold increases. Under the negative electrode, the cathode, the membrane voltage is reduced. At When the stimulus threshold is reached, the cell automatically triggers an action po potential.

The known stimulation current devices work with the different Form impulses in the low-frequency spectrum of approx. <0-200 Hz (NF current). There are z. B. the so-called triangular currents, Rech Teak currents, diadynamic currents, high-voltage currents, ultra-stimulating currents me, Faradic currents, to name just a few, are used. Some currents have a DC component, which means that polaritarian effects are still supported.

There are two frequency-dependent methods, action potentials thera to use:

• - Function imitation principle:
  You determine the number of action potentials that the excitable cell (nerve or muscle) generates to accomplish its tasks. In therapy, as many impulses are then generated by irritation in the corresponding cell, so that the cell is supported in fulfilling its tasks. So z. B. stimulated to generate up to 6 individual contractions per second with a frequency of up to 6 Hz.
• - Fatigue principle:
  If, on the other hand, the cell (nerve or muscle) is forced to form action potentials by stimulation with a higher frequency, much more often than it would have to do to fulfill its tasks, it will tire after a short time. The opposite effect occurs. Fatigue can be explained by energy-consuming processes in the creation of action potentials. So a hardened muscle can be relaxed according to this fatigue principle by using it with a "high" frequency of e.g. B. 100 Hz or 200 Hz.

Of course, in order to generate any action potential the intensity should be chosen so high that the stimulus threshold above is taken. The level of the intensity to be set depends on fol factors:

• - the position (depth) of the cell to be irritated in the tissue (distance from the electrode),
• - on the size of the electrodes and
• - of the fabric resistances in the flow area, which like are therefore influenced by the parameters of the current form.

In practice, the current shape and electrode size are specified. Around now at a certain distance from the electrode (e.g. in the tie fe of the tissue) to irritate a group of cells, the intensi  vity increased until there is potential for action. Perhaps the disadvantage here is that cells between the stimulus and the electrode and have no higher stimulation thresholds, be irritated at lower intensities.

Even with cells that have higher stimulus thresholds, the Pra xis "simple" (this is not always possible due to the stress on the skin) the intensity of the current pulses increases.

With increasing intensity, they become deeper and deeper one after the other lying cells or cells that are getting farther from the electrodes lying away, irritated.

With the apolaritarian stimulus principle only so-called medium-free come quent alternating currents (Mf currents) without any direct current com component for use. Mf currents are sinusoidal AC currents with a frequency of <1000 Hz-100000 Hz ne single vibration (alternating pulse) is with sufficient intensity polarity effective. A cure that is inherently polaritarian zen alternating pulses resulting alternating current (Mf pulse) can trigger an action potential in a nerve or muscle cell.

There is a "summation effect". With increasing frequency higher and higher intensities are also needed in order to promote action trigger in the cells. WYSS has proven beyond any doubt sen that the generation of action potentials with Mf pulses lig is independent of polaritarian effects. It means that wherever the intensity and the number of vibrations is large enough, action potentials are generated regardless of the current polarity of the Mf current (WYSS, Oscar A. M .: Principles of electrical stimulation. NEW YEAR'S SHEET, out by the Natural Research Society in Zurich for the year 1976, Commission publisher Leemann AG Zurich, 1976, 28-34).  

There are Mf pulses in the Nf rhythm of <0- approx. 200 Hz and Mf- Carrier frequencies of <1000 Hz-100000 Hz are used. In the Pra This is usually a sinusoidal amplitude-modulated Mf current (AM-Mf-Strom) The following principles are consistent with those in Verbin with the "polaritarian stimulus principle" described.

• - Function imitation principle:
  In sync with the Mf pulses (AM ′ 5 frequency) there are action potentials in controllable cells. The cell is thus stopped to perform its natural functions that result from this frequency.
• - Fatigue principle:
  In order to tire excitable cells, Mf pulses with higher AM's frequencies are used.

As the current intensity increases, they become deeper and deeper one after the other cells (further away from the electrodes) are irritated.

As the Mf carrier frequency increases, more and more intensity is required to generate action potentials (WYSS, loc. Cit., 41-43, Fig. 17 / p. 41, Fig. 18 / p. 42). The images are courtesy of Professor Dr. Oscar AM WYSS taken from the booklet "Principles of Electrical Irritation". Fig. 17 and 18 show the dependence of the stimulus thresholds on medium-frequency impulses as a function of the carrier frequency. The following additional therapy options are available on the basis of the medium-frequency alternating currents:

If sufficient intensity is stimulated with (amplitude-constant) Mf current, an action potential first arises. In the case of Mf current that flows for a long time, the falling leg of the action potential remains at a level of depolarization (permanent depolarization) that makes up about half of the rest voltage. After switching off the Mf current, the membrane voltage drops to the level of the rest voltage with a delay (WYSS, loc. Cit., Fig. 13 / p. 36). The following sub-points describe the therapeutic use of permanent depolarization.

blocking Pain relief and influencing blood circulation

At high intensities, depending on the nature of the treatment area on the tolerance limit, it comes through permanent polarization to block nerve transmission routes. This real nerve blockage (the proof was published by BOWMAN, Bruce R., 1981, dissertation E.K. University of Ljubljana, Rancho Los Amigos Hospital, Downey, California USA, delivered) is z. B. for pain blockage in phantom pain or for stellate blockade with circulatory disorders used.

Muscle contracture Muscle training for weakness of the voluntary innervation and muscle strain

If the nerve-muscle apparatus is intact, permanent depolarization will result on the striped muscle (skeletal muscle) directly irritated. It is coming for muscle contracture, the z. B. with voluntary weakness of innervation the muscles or to stretch the antagonists of spas muscle is used. The intensity is said to be during the Treatment is interrupted at short intervals by breaks become. The intensity can also be between 100% and approx. 50% of the set value can be swelled and swelled.

Generation of strong muscle contraction forces

It can be very powerful muscle without fatigue contractions are generated. With tetanic contraction, the can be generated with stimulation current of approx. 50 Hz and higher, however, there is a rapid decrease in muscle contractions force through fatigue of the motor units.

Cell division Wound healing and accelerated bone healing

Permanent depolarization occurs in healthy cells Cell division. So z. B. supports wound healing and Bone healing in fractures can be accelerated.

With Mf currents it comes under the influence of the electrical Alternating field also for back and forth movement (shaking effect) accompanied by charged molecules in the tissue through which they flow of rotational movements of the charged molecular parts. Hereby becomes a higher chance of "correct" encounter position of enzyme and substrate achieved in metabolism processes react chemically with one another (metabolizer relief). The shaking effect affects concentration arbitrary by diffusion processes based on existing concentration gradients in certain directions preferentially run through the additionally communicated kinetic Energy are accelerated (Mf iontophoresis, inflammation inhibition, pain relief).

The shaking effect is particularly effective at high intensities.

Distribution of inflammation and pain mediators Anti-inflammatory and pain relief

In painful, inflammatory processes there is sick Tissues regularly a high concentration of inflammatory and pain mediators. Due to the shaking effect, this becomes ho  he concentration reduced (distributed). The "shaking intensity", caused by high current intensities is just like that Frequency of therapeutic effects of great importance tung (HANSJURGENS, MAY, electrical differential therapy, Karlsruhe 1990).

Metabolic effects (diffusion, mitochondria, cAMP) Metabolism relief and metabolism promotion

As described above, the biochemical drains change processes easier.

Mf current is also found when cell cultures flow through that the number of mitochondria ("power plants" of the Cells) and their size has increased significantly (KOMITOWSKI and EHEIINN 1990, internal communication).

An important cell messenger, the cAMP, can also pass through Mf current can be influenced in its concentration. There is one Mf intensity dependency (DERTINGER, 1989) trum Karlsruhe, NAGY, Nemectron GmbH Karlsruhe).

With Mf currents can also be a pain-free vigorous Muscle contraction can be generated in the form of muscle contracture. From 8 kHz there is a so-called "threshold dissociation", i. H. the threshold current strength for muscle contractions occurs below that of the sensitive threshold (EDEL, H .: primer of electrodiagnostics and elec trotherapie, Müller & Steinicke Munich 1983, p. 193). It can strongest muscle contractions are triggered without pain. From a therapeutic point of view, the threshold dissociation is particularly in interesting when using the reversible process of muscle con tract caused by the permanent depolarization of the Mf current will call.  

Due to high intensities of the Mf current in the Ge weave generates heat. The precondition is, however, that it is not to be nuisance to the patient by exceeding the thresholds (Sensation, muscle, tolerance, pain) comes.

Anolog to improve the metabolic processes can with Mf- Current also an iontophoresis can be achieved, i.e. an introduction of drugs with the help of the current through the skin in the body by. Due to the physical conditions you need for Iontophoresis with Mf current compared to galvanic Stream a longer treatment time and higher intensities.

As described above and in so far also in the relevant Read specialist literature (cf. book "EDiT® - Electrical Differential Therapy "by A. HANSJÜRGENS and H. U. MAY, © 1990, Nemectron GmbH, Karlsruhe) work the well-known Electrotherapy devices, depending on the findings, with low-frequency currents or with amplitude-modulated medium-frequency currents with Fre sequences of <0-200 Hz or with medium frequency currents with a Frequency from <1000 Hz to 100000 Hz with constant ampli tude (intensity).

The object underlying the present invention is therein an electrotherapeutic device of the generic type admit with the same and in so far synergistically with low and medium frequency currents achievable therapeutic Effects are achieved.

This object is achieved in that the Ar frequency in a frequency band of up to several kHz with a periodicity in the LF range from <0 to approx. 200 Hz is dulated.  

In other words than those used in the patent claim Technical teaching of the electrotherapeutic according to the invention Device in one of the medical report and the conjugator to use appropriate medium-frequency electricity for electrotherapy choose and the frequency of the medium-frequency current in a fre frequency band of, for example, 2000 Hz with a modulation frequency frequency of <0-200 Hz, d. H. with a frequency of LF currents, pe to vary periodically. The device according to the invention thus works according to the laws of frequency modulation (and not as from the State of the art known, according to the laws of amplitude dulation).

The Mf currents with constant amplitude (intensity) are therefore to generate action potentials in a low-frequency rhythm (NFR) used.

In contrast, in all known stimulation current methods to Er generation of action potentials the intensity of the stimulation current in the low frequency rhythm (NFR <0- approx. 200 Hz) up and down The level of the intensity of the respective impulses (Nf impulse or Envelope of the Mf pulse) depends on the stimulus threshold of the cell to be irritated and the distance between the cell and the electrode. With deeper cells, a higher intensity is needed to to compensate for the voltage drop across the fabric Electrode and the cells to be irritated are formed. The curve of the stimulus threshold will increase with each pulse with rising and with falling the intensity (vertical).

The electrophysiological background of the Leh according to the invention re is as follows:

The dependence of the stimulus threshold on the intensity and the Fre quenz has already been described. The higher the frequency of the strobe mes, the greater its intensity must be in order to increase the stimulus threshold  exceed. These linearly rising curves are electrophysiological shear thresholds can now not only by changing the Stro intensity, but also by varying the frequency over or be undercut.

In the method of frequency modulation according to the invention which now only uses Mf currents. The intensity will kept constant during treatment after being on the desired value was set. The carrier frequency of the ampli constant Mf current is modulated in the NFR (FM-MF current), taking the curve of the stimulus threshold as it falls and up again increasing frequency is passed horizontally. So it comes synchronous to the NFR for the generation of action potentials.

Developments and special refinements of the fiction Basic principles are the subject of the subclaims.

The details are as follows based on the other drawings explained in more detail. These show in

Fig. 1 is a schematic representation of the frequency-modulated medium-frequency stimulation with current;

FIG. 2 shows a detail from FIG. 1 to explain a frequency window in the current-frequency diagram;

. Fig. 3 shows the detail of Figure 2 in the frequency-time diagram;

Fig. 4 is an illustration of a frequency-modulated MF current;

FIG. 5 shows a variation of the frequency window of FIG. 3;

Fig. 6 is a schematic diagram of irritation (interference) with amplitude-modulated medium-frequency current;

Fig. 7 is a representation of Figure 6 with variable pacing rate.

FIG. 8 shows a representation according to FIG. 1 with two overlapping frequency-modulated medium-frequency currents;

Fig. 9 is a block diagram of an apparatus according to the invention;

Fig. 10 is a control panel of the device of Fig. 9;

FIG. 11 is a bipolar electrode system;

Fig. 12, an action potential.

Fig. 1 shows in the current (I) - frequency (f) - diagram the known representation of a stimulus threshold RS with the divergence from the Nf range from scattering range (see. WYSS loc. Fig. 18).

In Fig. 1, the frequency of the Mf current between values f3 (lowest frequency) and f4 (highest frequency) is modulated in the low-frequency rhythm (NFR). f3 and f4 are to be referred to as corner frequencies of the resulting frequency window.

The area of the entire frequency window is shown enlarged in the upper part of FIG. 1, the course of the FM-Mf current as well as that of the stimulation threshold and that of the frequency modulation curve (FM curve) being shown in time. The frequency of the FM curve is f1, so it has a value from the NF range. (An example of a frequency-modulated curve is shown in Fig. 4). For e.g. B. f1 = 2 Hz, two action potentials 1 are generated per second, since the stimulus threshold RS3 is surpassed every time the frequency f3 is reached with the set intensity of the Mf current. At the time of f4, the constant intensity of the Mf current is no longer large enough to reach the stimulation threshold RS4.

To be able to generate action potentials with FM-Mf currents in the NFR The following interdependent parameters must be correctly entered be put:

• - the carrier frequency of the Mf current,
• - the amplitude of the Mf current,  
• - the modulation frequency and
• - The corner frequencies of the frequency modulation (frequency window).

According to the respective therapeutic requirements that apply to Anwen of FM-Mf currents and the use of action potentials as well as the effects of the Mf current will allow the carrier frequency of the Mf current selected. So the following effects against the Mf current at the same time as those of the action potentials are used: heat generation, Mf iontophoresis, as well as strong or weaker anti-inflammatory, pain relief and fabric influencing exchange.

The intensity of the Mf- Current (constant amplitude). The intensity is chosen so that the threshold is not yet exceeded.

Then the modulation frequency of the FM according to the therapeuti principles of imitation of function or fatigue sets.

Finally, the corner frequencies of the frequency window are selected, ie the frequency limits between which the carrier frequency is to change in the NFR. The frequency window must be chosen at least so large that it surely leads to horizontal exceeding of the smoldering curve in the range of the predetermined carrier frequency. The frequency required for this is the lower frequency limit (f3 and point P23, in Fig. 2) of the frequency window; the upper frequency limit is the selected carrier frequency (f4 and point P24, in Fig. 2).

• - The advantages of this based on Fig. 1 (with Fig. 2 / Fig. 3) Darge presented method is that simultaneous therapeutic effects of action potentials d Mf current effects (shaking effect) with and without heat generation are possible.

All additional therapy options with amplitude-con constant Mf current (ak-Mf current) can be given simultaneously with the therapeutic effects generated by FM-MF electricity th action potentials and heat are used, for. B. for Pain therapy with and without warmth.

Furthermore, new therapy combinations with and without heat are possible, namely, new combinations of the effects of the Mf current (permanent depolarization and shaking effect) and the action potentials generated by FM-MF currents can be combined by varying the time and intensity of the FM curves and the same treatment are used (see later Fig. 5).

Permanent depolarization is used:

• - to block cell information - e.g. B. for pain block de for phantom pain and for stellatum blockade Circulatory disorders and
• - in healthy cells for cell division - e.g. B. in treatment of wounds and fractures.

The shaking effect is used:

• - for pain mediator distribution,
• - for the distribution of inflammation mediators,
• - Concentration-compensating processes between the cell len,
• - to influence metabolic processes and
• - for iontophoresis with medium-frequency currents.

The muscle building is favored, and at the same time Shaking effects, without developing heat that can be used therapeutically.  

The frequency f is in the lower Mf range, so that the required intensity of the Mf current does not yet generate any heat.

With reference to FIG. 2, it should also be noted that the following effects can be achieved by varying the FM curve in terms of intensity:

• - to generate slow waves of contracture (detection of deeper and not so deep motor units) can the frequency f of the Mf currents in several seconds from f5 (Point P25) after f3 (point P23) and back again after f5 be changed.
• - To generate longer treatment phases between the Action potentials in which the cell can recover and only the shaking effect is generated, the frequency f of the Mf Currents can be changed from f3 (point P23) to f6 (point P26) and not just from f3 (point P23) to f4 (point P24), as it is for Generation of action potentials is necessary.

Fig. 3 shows several FM curves in which both the working frequency f (see FM curves I + II with III) and the corner frequencies (see FM curve I with II) are varied. The variation of the corner frequencies has the effects described in FIG. 2, while the change in the working frequency generates additional heat due to the higher current intensity (see FIG. 2 point P24 with point P44 at F4).

Muscle building is achieved through simultaneous heat generation Choice of a higher working frequency f of the Mf also promoted. By using amplitude constants according to the invention medium-frequency currents lead to further electrophysiological Advantages of this method in irritation:

• - No NF irritation of the skin due to changes in the intensity of the Stimulation current, thereby painless application;  
• - bundled penetration of the streamlines perpendicular to the skin layers, thereby only low energy losses of the electricity overcoming the skin barrier and high irritation subcu tan and in depth;
• - Exploiting the low skin resistance of the Mf current (with skin resistance decreases with increasing frequency), thereby painless use and low energy loss of the Current in overcoming the skin barrier;
• - decreased feeling of electricity after a few minutes of treatment by permanent depolarization of the Mf current.

Based on Fig. 5 is shown such. B. the following effects can be produced one after the other by temporal variations of the FM curve (fFM-K has the meaning of an adjustable fixed frequency):

• - tetanic contractions (fFM-K <20 Hz),
• - pause (fFM-K = 0, f of Mf = upper corner frequency),
• - contracture (f of Mf = lower corner frequency),
• - Pause (fFM-K = 0, f of Mf = upper corner frequency) and again
• - tetanic contractions (fFM-K <20 Hz) etc.

In the upper part of the illustration according to FIG. 5, an FM curve varied between the corner frequencies f3 and f4 is shown. Action potentials are generated in the curve area E and at the same time there is a heat effect. After a predetermined period of time, the corner frequency f3 is changed insofar as - according to the curve H which is varied compared to G - the effective depth is reduced. In the further course of time, only heat is generated at constant current (see F).

In the lower part of the illustration in FIG. 5, a further treatment curve is shown. First an FM curve with the corner frequencies f1 and f2 is set, which generates action potentials; Due to the lower frequencies - unlike in the upper curve - no heat is generated (see A). The FM curve is replaced by a pause in stimulation (cf. B), namely at a level above the base frequency f2; the required current is not sufficient to generate heat. A current is then applied at a frequency which is lower than the lower corner frequency f1 to produce a contracture and / or block (cf. D). After that, action potentials are again generated (cf. C) and also without heat generation.

Based on FIG. 1. . . 5, the generation of action potentials was shown on the basis of the frequency-modulated working frequency according to the invention. To about Figs. 6, 7 and 8, further developments in the sense will be apparent that two Mf streams are brought into superposition (interference method). This results in amplitude modulation (AM) in the overlapping field of both Mf currents.

Amplitude-modulated currents thus arise, the exact processes being shown in FIGS. 6 and 7. The AM arises from the frequency difference of the two Mf currents. A current has a fixed center frequency of, for example, 4000 Hz, the other circuit has a fixed frequency, the z. B. can be set between 3800 Hz and 4000 Hz. Interference occurs in areas where the two currents overlap. Has the circuit with an adjustable frequency z. B. a frequency of 3950 Hz, there is an amplitude-modulated medium-frequency current, the amplitude of which is modulated with 50 Hz (see. Fig. 6). Ranges between 3800 Hz and 4000 Hz can also be modulated with a very slow frequency <0- approx. 0.1 Hz. However, this is not done for the purpose of generating action potentials and should not be confused with the FM of the preceding invention. After all, neither the modulation frequency between <0-200 Hz, nor the frequency window of 200 Hz is sufficient to generate any action potential.

Fig. 7 shows an example with a modulation frequency of 1/15 Hz and a frequency range of 80 Hz-120 is shown Hz. So who created the 80 action potentials, which increased continuously to 120 in 15 seconds.

In the interference method, the AM takes place in the two directions of the 45 ° line and with a phase shift of 90 ° in the direction indicated by a line perpendicular to the 45 ° line (cf. FIGS. 6 , 7 , dashed line) is.

Fig. 8 shows the resulting current of an FM-Mf stimulation when two currents are superimposed. The aim of such an overlay of two or more circuits is to increase the intensity in the overlay area (treatment area) by adding the individual intensities to the extent that action potentials are triggered and heat is generated.

If the phase difference of both currents = 0, the intensity increases only in the directions of the 45 ° line (cf. FIG. 8). If, on the other hand, the phase is rotated by 180 ° with a periodicity of <0 to approximately 0.1 Hz, the intensity increases alternately in the 45 ° directions and in the two directions perpendicular to the 45 ° line (see Fig. 8, dashed line).

Also, the frequencies of both currents can have a different value, so that, as shown in FIGS . 6 and 7, AM occurs in the overlay area. Due to slow FM of the FM-Mf stimulation according to the invention, action potentials are triggered by the AM at f3 (cf. FIG. 1), at M4 then only the Mf shaking effect and possibly heat acts.

Fig. 9 shows a block diagram of an inventive electrotherapeutic device for one and also for two circuits.

The electrotherapeutic device shown in FIG. 9 basically consists of an oscillator 10 , to which one (or more) amplifier 11 is (are) coupled in parallel. Each amplifier 11 is assigned a patient connection 12 via which - diametrically opposite one another - electrode connections are applied to parts of the body to be treated. The oscillator 10 is connected to a frequency generator 13 which determines the actual operating frequency fMf; the oscillator 10 is also assigned a frequency modulator 14 via which the operating frequency fMf is modulated within the predetermined corner frequencies.

Fig. 10 shows a circuit board of an inventive electrothermal device, this device is shown as simple by means of operating buttons and as a portable home device can also be operated by lay people. Depending on the therapy, the different currents and frequencies can be set and it is equally conceivable to connect this device to a control module (microprocessor) which initiates specific treatment programs in accordance with the options shown in FIG. 5.

In Fig. 11, a 2-pole electrode system is shown as an application example of an electrotherapeutic device working according to the specified specifications and boundary conditions. In order to achieve the intended effect in the vicinity of the electrodes 20.1 , 20.2 , it must be ensured that in the treatment area 21 the current density, that is to say the current intensity per unit area, is sufficiently high. This is achieved according to the system shown with a closed circuit via the two electrodes and through the treatment area. The highest current densities and the associated therapeutic effects arise in each case near the electrodes, ie in the treatment area (cf. the areas highlighted in FIG. 11).

If the treatment area is in depth, then - cf. Figures 6, 7 and 8 -. Four electrodes, that is, two circuits designed so that there is a superposition field in the depth of the tissue, thus in the treatment area. In this area, the intensity is specifically increased by adding the intensities of both circuits.

Claims (7)

1. In the medium frequency range between 1000 Hz and 100000 Hz ar working device for electrotherapeutic applications, with respect to a body part to be treated one or more circuits, each with pairs diametrically opposite or ne adjacent electrodes, characterized in that the working frequency in one Frequency band from several hundred to a thousand Hz (corner frequencies) with a periodicity of <0 to about 200 Hz is frequency modulated. 2. Electrotherapeutic device according to claim 1, characterized records that the working frequency with the associated Eckfre sequences are chosen so that additional heat generation arises. 3. Electrotherapeutic device according to claim 1 or 2, characterized characterized in that a control module (microprocessor) inte the corner is considered over the treatment time frequencies and / or the modulation frequency are variable. 4. Electrotherapeutic device according to one of claims 1 to 3, characterized in that the modulation frequency in addition is modulated in a range from <0 Hz to about 0.1 Hz. 5. Electrotherapeutic device according to one of claims 1 to 4, characterized in that two or more circuits superimpose, the frequency of a circuit of  the frequency of the other circuit by an amount from 0 to differs about 200 Hz. 6. Electrotherapeutic device according to claims 1 to 5, there characterized in that a phase difference - with constant Value or modulated in the range from <0 to about 0.1 Hz - between exists in both streams. 7. Electrotherapeutic device according to one of claims 1 to 6 characterized by his training as Home device.